Abstract:
A method of adjusting and using operating parameters of a transmission of a vehicle may include accessing a stored list of clutch parameters, performing a dynamic condition procedure while the vehicle is driven to revise minimum on-coming apply pressure for each friction element based on a sensed performance of an element within the vehicle powertrain, storing the modified minimum on-coming apply pressures, and operating the vehicle. A related transmission control device operates a transmission using parameters obtained during a dynamic condition procedure.
Abstract:
A method of determining automatic transmission lubrication fluid flow rates corresponding to a running vehicle without direct oil flow measurements is disclosed. A set of in-vehicle clutch torques for a chosen clutch pack during a gear shift event for a set of shift conditions is obtained. A series of bench tests at various clutch-pack clearances and oil-flow rates for the set of shift conditions are performed. The clearances and oil-flow rates are adjusted in response to the measured magnitudes exceeding thresholds. In-vehicle transmission lubrication oil-flow rates are estimated at the chosen clutch pack for the set of shift conditions when the bench-test and in-vehicle clutch torques are less than the thresholds. The steps are reproduced for other engine conditions and fluid temperatures corresponding to other transmission gear positions. A functional map of in-vehicle oil flow rates are produced, and the transmission is adjusted based on the map.
Abstract:
A transmission includes first and second input shafts connected via a first clutch to a power source, an output shaft, a first shift gear group including shift gears arranged between the first input and output shafts, a first switching mechanism including a synchronizer for selecting one shift gear from the group, a second shift gear group including shift gears arranged between the second input shaft and the output shaft, and a second switching mechanism including a synchronizer for selecting one shift gear from the group. In order to learn a synchronizer balk position, either the first or second shift gear group, where no targeted synchronizer belongs, is set to any shift gear, both the first and second clutches are engaged, the balk position of the synchronizer is detected in a process of the targeted synchronizer being slid, and information specifying the detected position is stored.
Abstract:
A method of determining automatic transmission lubrication fluid flow rates corresponding to a running vehicle without direct oil flow measurements is disclosed. A set of in-vehicle clutch torques for a chosen clutch pack during a gear shift event for a set of shift conditions is obtained. A series of bench tests at various clutch-pack clearances and oil-flow rates for the set of shift conditions are performed. The clearances and oil-flow rates are adjusted in response to the measured magnitudes exceeding thresholds. In-vehicle transmission lubrication oil-flow rates are estimated at the chosen clutch pack for the set of shift conditions when the bench-test and in-vehicle clutch torques are less than the thresholds. The steps are reproduced for other engine conditions and fluid temperatures corresponding to other transmission gear positions. A functional map of in-vehicle oil flow rates are produced, and the transmission is adjusted based on the map.
Abstract:
A transmission includes first and second input shafts connected via a first clutch to a power source, an output shaft, a first shift gear group including shift gears arranged between the first input and output shafts, a first switching mechanism including a synchronizer for selecting one shift gear from the group, a second shift gear group including shift gears arranged between the second input shaft and the output shaft, and a second switching mechanism including a synchronizer for selecting one shift gear from the group. In order to learn a synchronizer balk position, either the first or second shift gear group, where no targeted synchronizer belongs, is set to any shift gear, both the first and second clutches are engaged, the balk position of the synchronizer is detected in a process of the targeted synchronizer being slid, and information specifying the detected position is stored.
Abstract:
A method may be provided for correcting a raw signal supplied by a pressure sensor in an all wheel drive system having a hydraulic pump and a hydraulic fluid. The method may include measuring the raw signal supplied by the pressure sensor, determining when the all wheel drive system is in a state where the hydraulic fluid is at a known pressure determined independently from the pressure sensor, determining a new zero-point offset by comparing the raw signal to a voltage value associated with the known pressure, and creating a corrected voltage signal by adjusting the raw signal based on the new zero-point offset. This corrected voltage signal may be converted into a pressure reading for controlling the all wheel drive system.
Abstract:
A vehicle includes a torque generating device, a transmission, and a controller. The transmission has one or more clutches. The controller executes a method, which includes measuring an amount of slip across an identified offgoing clutches and determining whether the offgoing clutches have slipped prior to a modeled clutch torque capacity reaching zero. A status is assigned indicating that the offgoing clutches are released if the offgoing clutch has slipped prior to the modeled clutch capacity reaching zero. The controller induces slip across the identified offgoing clutches to a calibrated low, non-zero level after recording the value, including by enforcing the low, non-zero slip value using one or more acceleration profiles.
Abstract:
A method of controlling and regulating a transmission brake which, for the purpose of synchronization, determines a target rotational speed of a shaft to be synchronized on the basis of an actual rotational speed of a transmission shaft, and controls a transmission brake such that the determined target rotational speed is set for the shaft that is to be synchronized. The transmission brake also carries out additional functions. These functions require no, or only minimal, additional hardware complexity in a cost-neutral way, but considerably increase the functional and practical value of the transmission brake. The comfort and speed of shifting operations, the protection or, as the case may be, the detection of error states in sensors, a clutch, a main clutch or a motor control are improved, and undesirable transmission states avoided. It is also possible to account for and influence other conditions, such as the operation of ancillary devices.
Abstract:
A method of adapting the characteristic curve of clutches in a partial dual-clutch transmission of a vehicle, for example a utility vehicle, having a first partial transmission in the form of a dual-clutch transmission (DKG) having a dual clutch (DK) that includes a first clutch (K1) and a second clutch (K2), which can be functionally connected to a drive engine (M), and a second partial transmission in the form of a main transmission (HG) which shifts with traction force interruption and which is arranged downstream from the dual-clutch transmission (DKG) in a drive-train. To achieve reliable and precise clutch control and a consistently high level of shifting comfort, the characteristic curve adaptation of the first and the second clutches (K1, K2) is carried out with the assistance of a pre-loading of the first and the second clutches (K1, K2), while the main transmission (HG) is in a neutral position.
Abstract:
A method for adapting a separating clutch in a drive train system of a vehicle, the drive train system having an electric machine, an internal combustion engine as well as an automatic transmission having an hydraulic torque converter and a torque-converter lockup clutch, and the separating clutch lying between the electric machine and the internal combustion engine, and the internal combustion engine being started by the electric machine while the electric machine drives the vehicle, having the following steps: in a time interval, the separating clutch is operated in slip operation for cranking up the internal combustion engine, in the time interval an expected rotary speed change of the electric machine is calculated, the rotary speed change expected by calculation is compared to the actually occurring rotary speed change for deviation and the deviation ascertained is used to adapt the separating clutch.